Shiftable fluid control circuit

ABSTRACT

A plurality of identical three-way normally open poppet valves are so interconnected between a source of momentary signal pressure and an output member or members as to shift this member or members between two alternate positions in response to successive momentary applications of fluid pressure.

United States Patent Huntington [54] SHIFTABLE FLUID CONTROL CIRCUIT[72] Inventor: Andrew B. Huntington, Waterford, Mich.

[73] Assignee: Ross Operating Valve Company, Detroit,

Mich.

22 Filed: Jan. 19,1970

21 Appl.No.: 3,613

[52] U.S. Cl "235/201 [51] lnt. Cl. ..G06m 1/12 [58] Field of Search..235/200, 201

[56] References Cited UNITED STATES PATENTS 3,001,698 9/1961 Warren..235/20l 3,550,847 12/1970 Scott ....235/201 3,242,946 3/1966 Chabrieret al. ..235/201 X 14 1 Feb. 15, 1972 3,243,113 3/1966 Welsh ..235/20l3,326,239 6/1967 Saint-Joanis et al. .....235/20l X 3,342,197 9/1967Phillips ..235/20l X 3,407,833 10/1968 Brandenberg... .....235/20l X3,502,267 3/1970 Kay .....235/20l 3,303,999 2/1967 Mamy ..235/201Primary ExaminerRichard B. Wilkinson Assistant Examiner-Lawrence R.Franklin Attorney-Harness, Dickey & Pierce [57] ABSTRACT A plurality ofidentical three-way normally open poppet valves are so interconnectedbetween a source of momentary signal pressure and an output member ormembers as to shift this member or members between two alternatepositions in response to successive momentary applications of fluidpressure.

4 Claims, 5 Drawing Figures SHEET 1 UFZ BACKGROUND OF THE INVENTION 1.Field of the Invention The invention relates to fluid control devices,and more particularly to mechanisms shiftable between two alternatepositions in response to momentary applications of fluid pressure.

2. Description of the Prior Art The prior art is exemplified by a numberof patents issued to the assignee of the present application, namely US.Pat. Nos. 2,859,735; 2,921,602; 2,997,066; 3,011,519 and 3,459,224. Insome of these prior art devices, mechanical locking means or detents areused to hold thevalve elements in certain positions during the cycle. InU.S. Pat. Nos. 2,997,066 and 3,459,224, no detents are used, but thesedevices have other deficiencies which it is an object of the presentinvention to overcome. Disadvantages of these prior constructionsinclude the fact that they are relatively expensive to construct, usering seals which impose pressure limitations, occupy considerable spaceand present substantial and undesirably variable frictional resistanceduring operation because of the nature of the valve structures. Thevalving elements in these prior constructions are also more susceptibleunder certain circumstances to sluggish action, leaking and/ormalfunction due to contaminants carried by the air lines and theireffect on materials and fits. In addition, none of the prior devices arecapable of simultaneously providing two output signals which areopposite in sense.

SUMMARY OF THE INVENTION According to the invention, a plurality ofidentical threeway normally open poppet valves are so interconnected asto obtain an on-off bistable output condition with a single input andwithout the use of mechanical latches. In fluid logic terms, each valveis a NOT element, and the system is a binary counter. These valves maybe in extremely small sizes such as for pilot control purposes. Bysuitable orientation, in side-toside and/or end-to-end contiguousmounting, with all ports opening into a common plane, the valves can becompactly interconnected in a common manifold arrangement.

Although control of the system's output conditions would normally beprovided by input pressure pulses of short duration, the trapping ofpressure in certain portions of this system during the cycle is carriedout by the poppet valves in such a way that no significant limitationneed be placed on any portions of the cycle time. The valving elementshave relatively short strokes and low frictional resistance thusincreasing reliability and rapidity of operation. The poppet valves areless susceptible than spool valves to hangup" due to contaminantscarried by the air line, and the problem of swelling and shrinking ofseals such as occurs in resilient sealed spool valves is avoided.

In the illustrated embodiment of the invention, ten such identicalpoppet valves are used.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of theindexing circuit shown at the beginning of a complete cycle with nosignal pressure being applied;

FIG. 2 is a cross-sectional view of a single valve shown in its normallyopen position;

FIG. 3 is a view similar to FIG. 1 but showing the positions of thevalves after the pressure of the first signal pulse has been applied andshowing the output member in its shifted position;

FIG. 4 is a view similar to FIG. 3 but showing the position of the partsafter the pressure of the first signal pulse has been removed; and

FIG. 5 is a view showing the positions of the parts after the pressureof the second signal pulse has been applied and the output member hasbeen shifted back to its original position.

DESCRIPTION OF THE PREFERRED EMBODIMENT The circuit is generallyindicated at 11 in FIG. 1 and comprises a signal line 12 which providesrepeated pneumatic pressure pulses to this system. The purpose ofcircuit 11 is to cause an output member l3-such as a three-way controlvalve to shift from one position to the other each time pulse pressureis applied at line 12, and to stay in its shifted position when thepulse pressure is removed.

The circuit comprises ten identical normally open threeway valvesindicated at 14, 15, 16, 17, 18, 19, 21, 22, 23 and 24. The constructionof each valve is shown in FIG. 2. The valve comprises a body 25 andcover plates 26 and 27 at the opposite ends secured to the body by bolts28. Cover plate 27 retains an insert 29 in body 25, this insert beingengageable at one end by a seal 31 carried by a counterbore 32 in thebody. Member 29 has an annular slot 33 within which is disposed a seal34. A supply port 35 is formed in body 25 between seals 31 and 34 and isconnected with a central bore 36 in member 29 by an annular groove 37and a radial passage 38 in member 29.

The inner end of member 29 has a valve seat 39 formed thereon. A spring40 in bore 36 of member 29 urges a valve disc 41 away from seat 39 andagainst another seat 42 surrounding a central passage 43 in body 25. Anoutput port 44 is formed in body 25 adjacent seat 39, so that pressureat either port 35 or 44 will press rubberlike disc 41 against seat 42.An exhaust port 45 is formed in body 25 connecting with a bore 46 whichleads to seat 42 through bore 43.

A piston 47 is disposed in bore 46, forming a chamber 48 therein towhich is connected a signal port 49. Piston 47 is movable between theposition shown in FIG. 2, as limited by cover plate 26, and a positionagainst disc 41, forcing this disc away from seat 42 and against seat39. The diameter of bore 46 is greater than that of seats 39 and 42, sothat signal pressure will overcome the supply pressure at port 35 or thepressure from port 44 plus the force of spring 40, which presses disc 41against seat 42.

Signal line 12 leads to the signal ports 49 of valves l7, 18, 19 and 21.It also has a branch 51 leading to the supply port 35 of valve 14, andthe output port 44 of this valve is connected by a line 52 to the signalport 49 of valve 15. This valve also hasa constant pressure connection53 to its supply port 35. The output port 44 of valve 15 is connected tothe supply port of valve 16 by a line 54. A line 55 connects the outputport of valve 16 to the signal port of valve 13 as well as the signalport of valve 24 and the supply port of valve 21. A line 56 connects theoutput ports of valves 21 and 19, and a line 57 connects the supply portof valve 19 with the signal port of valve 22.

A branch 58 from line 12 is connected to the supply port of valve 22,and a line 59 connects the output port of valve 22 with the signal portof valve 23. The supply port of valve 23 is connected to a constantpressure line 61, and the output port to a line 62 which connects itwith the supply port of valve 24. The output port of valve 24 isconnected by a line 63 to the signal port of valve 16 and the supplyport of valve 18. The output ports of valves 17 and 18 are connected bya line 64, and a line 65 connects the supply port of valve 17 and thesignal port of valve 14. Output valve 13 has a supply port connected toa line 66 and a line 67 connected to the output port.

The operation of circuit 11 is as follows:

Starting with a condition in which output valve 13 is in its exhaustposition, as shown in FIG. 1, and no pressure is ap plied at signal line12 but with constant pressure being applied at lines 53, 61 and 66 asstated above, pressure will exist in lines 54, 55, 56, 57 and 62 withthe valves in their FIG. 1 positions. It will be noted that valves 14,15, l6, l7, 18, 19,21 and 23 will be in their open or supply positionswhile valves 22 and 24 are in their closed or exhaust positions.Pressure will exist in lines 54, 55, 56 and 57 leading to the signalports of valves 22 and 24. However, since line 63 is exhausted throughvalve 24, no pressure will exist in lines 64 or 65.

Upon application of signal pressure to line 12, valves l5, 17, 18, 19and 21 will be shifted to their closed or exhaust positions. Shifting ofvalve 15 will causelines 54 and 55 to be exhausted. This will causecontrol valve 13 to shift to its open pressure which will startrepetition of the cycle described above.

It will be observed that line 63 may be considered a second output linesince its pressurization and exhaustion are always position as shown inFIG. 3. Shifting of valves 19 and 21 to 5 exactly the opposite of firstoutput line 55. Thus, a second their closed positions however willprevent line 57 from being controlled member 68 shown in dot-dash linescould be conexhausted so that air will be trapped in this line, holdingvalve nected to output line 63, similarly to controlled member 13 22 inits exhaust position andthereby holding valve 23 in its WhlCh 1Connected I output lin Elther 1' bo h of Corlsupply position. Thus,pressure will be applied through line 62 O trolled members 13 and 68could be connected to the circuit, and open valve 24 to line 63,shifting valve 16 to its exhaust 1 and if both are connected, they willoperate simultaneously position as shown in FIG. 3. but in oppositedirections. I I

The parts will remain in the FIG. 3 position until the signal A summaryof a complete cycle of operation for the various pressure at line 12 hasbeen removed. Upon relief of the signal V lines is shown below: a

Line Signal Out- 12 52 54 55 57 59 62 63 65 put 67 Fl ure 3 P First"{Figure 4 E E P E 1; 2 1 5 g F1 11 5... P E P P l Semd actuam 1. E E PP P p g p g 1}? Repeat 1st actuation i"- g g g E 1 P P F'sIIP EPPEPEEPERepeat actuamn 1. E E P P P E P E E E No'rE.P=pressurized-, E=exhausted.

pressure at line 12, valves l5, l7, 18, 19 and v returned to their openor supply positions as shown in'FlG. 4. The pressure in line 57 will beexhausted by flowing from port 35 to port 44 of valve 19, hence throughline 56 and ports 44 and 35 of valve 21, through line 55 and valve 16 toexhaust. This will permit valve 22 to shift to its open or supplyposition, although valve 23 will not be shifted thereby since no signalpressure exists. Pressure will thereby be maintained in line 63, thusholding valve 16 in its exhaust position and maintaining the position ofcontrol valve 13. Shifting of valves 17 and 18 to their open positionwill permit pressure to be applied to line 65, shifting valve 14 to itsexhaust position as shown in FIG. 4. This will permit valve to return toits open position although the pressure from line 53 will have noimmediate effect because of the closed position of valve 16.

The second application of signal pressure to line 12 will .cause valvesl7, l8, l9 and 21 to be shifted to their closed or exhaust positions andvalve 23 shifted to its exhaust position through valve 22 and line 59,as shown in FIG. 5. Since valve I 24 is in its open position as seen inFIG. 4, the shifting of valve 23 to its exhaust position will result inline 63 being exhausted. This in turn will permit valve 16 to shift toits open position, so that the pressure from line 53 passing throughvalve 15 and line 54 will be applied to line 55 and shift control valve13 to its open or exhaust position as shown in FIG. 5. At the same time,valve 24 will be shifted to its exhaust position by pressure throughline 55. Exhaustion of line 63 by the shifting of valve 23 will notoccur before valves 17 and 18 will have shifted to their closedposition. Thus, pressure will be retained in line 65 so that valve 14remains in its closed or exhaust position. This will assure that valve15 remains in its open position so that pressure is maintained in line55 which holds control valve 13 in its exhaust or closed position.

Upon removal of the second application of signal pressure from line 12,the parts will return to their H0. 1 position. That is, valves 17, 18,19 and 21 will return to their open positions, the movement of valves 17and 18 permitting line 65 to be exhausted through line 63 and valve 24.This will permit valve 14 to shift to its open position, although thiswill not affect the position of valve 15 because there is no signalpressure. Thus, the pressure from line 53 will still be applied throughvalve 15, line 54, valve 16 and line 55 to signal port 49 of controlvalve 13, maintaining the control valve in its closed or exhaustposition. The pressure in line 55, plus the shifting of valves 19 and 21to their open positions, will cause shifting of valve 22 to its exhaustposition, thereby permitting valve 23 to shift to its open or supplyposition. However, this will have no immediate effect since valve 24remains in its closed position, but the valves i e il.EQEQUIEQEEQLIH?HQEHE'iGifiQE9l8 T he viii J55 r e'fejr'rdio in "Cain's4 through '9 as; assist? What is claimed is: 1. In a circuit forshifting a controlled member between two positions in response tosuccessive momentary signal pulses, a

signal pulse line, an output line controlling said controlled member, aplurality of substantially identical threeway normally openpressure-operated poppet valves, each of said valves having supply,output and exhaust ports, a signal'port, and means responsive topressure at said signal port for shifting the valves from a position inwhich said supply and output ports are connected to a position in whichthe output and exhaust ports are connected, constant pressureconnections to the supply ports of two of said poppet valves, and meansinterconnecting all of said poppet valves with each other and with saidsignal pulse and output lines whereby, starting with a condition inwhich pressure from one of said constant pressure connections is appliedthrough two of said poppet valves in series to said output line,application of a first signal pressure will cause both of said twolast-mentioned valves to shift to a position exhausting said outputline, release of said first signal pressure will cause the second ofsaid two valves to move to its supply position but maintain the exhaustposition of said first valve, thereby maintaining the exhaust conditionof said output line, application of a second signal pressure will causesaid first valve to move to its supply position whereby both valves areopen and said pressure source will pressurize the output line, andrelease of said second signal pressure will still maintain both of saidvalves in their supply position thereby maintaining the pressurizedcondition of said output line, said signal pulse line being connected tothe signal ports of third,

fourth, fifth and sixth poppet valves, said output line being connectedto the supply port of said third poppet valve, the

output ports of said third and fourth valves being connected, the outputports of said fifth and sixth valves being connected,

said signal pulse line being further connected to the signal port ofsaid second valve through a seventh valve, the supply port of said sixthvalve being connected to the signal port of said seventh valve, a lineconnected to the supply port of said fifth valve and the signal port ofsaid first valve, eighth and ninth valves in series with a'secondconstant pressure source for controlling said last-mentioned line, aconnection between said output line and the signal port of said ninthvalve, a con nection between said signal pulse line and the signal portof said eighth valve, and a tenth valve in said last-mentionedconnection, the supply port of said fourth valve being connected to thesignal port of said tenth valve.

2. The combination according to claim 1, each of said valves having abody, a relatively narrow bore in said body, a supply port at one end ofsaid bore, a pair of spaced seats in said bore, a valve disc disposedbetween said seats, the first of said seats separating said supply andoutput ports, the second seat separating said output and exhaust ports,and a wider bore in said body carrying a signal-actuable member wherebypressure at said supply or output ports without pressure at said signalport will cause said disc to engage said second seat and pressure atsaid signal port will cause the disc to move against said first seat.

3. The combination according to claim 2, each valve being furtherprovided with a spring urging said valve disc against said second seat.

4. The combination according to claim 1, further provided with a secondcontrolled member, said line which interconnects the supply port of saidfifth valve, the signal port of said first valve and the output port ofsaid ninth valve comprising a second output line and controlling saidsecond controlled member, application of said first signal pressurepressurizing said second output line, release of first said signalpressure maintaining the pressurized condition of said second outputline, application of said second signal pressure exhausting said secondoutput line, and release of said second signal pressure maintaining theexhausted condition of said second output line.

1. In a circuit for shifting a controlled member between two positionsin response to successive momentary signal pulses, a signal pulse line,an output line controlling said controlled member, a plurality ofsubstantially identical three-way normally open pressure-operated poppetvalves, each of said valves having supply, output and exhaust ports, asignal port, and means responsive to pressure at said signal port forshifting the valves from a position in which said supply and outputports are connected to a position in which the output and exhaust portsare connected, constant pressure connections to the supply ports of twoof said poppet valves, and means interconnecting all of said poppetvalves with each other and with said signal pulse and output lineswhereby, starting with a condition in which pressure from one of saidconstant pressure connections is applied through two of said poppetvalves in series to said output line, application of a first signalpressure will cause both of said two last-mentioned valves to shift to aposition exhausting said output line, release of said first signalpressure will cause the second of said two valves to move to its supplyposition but maintain the exhaust position of said first valve, therebymaintaining the exhaust condition of said output line, application of asecond signal pressure will cause said first valve to move to its supplyposition whereby both valves are open and said pressure source willpressurize the output line, and release of said second signal pressurewill still maintain both of said valves in their supply position therebymaintaining the pressurized condition of said output line, said signalpulse line being connecteD to the signal ports of third, fourth, fifthand sixth poppet valves, said output line being connected to the supplyport of said third poppet valve, the output ports of said third andfourth valves being connected, the output ports of said fifth and sixthvalves being connected, said signal pulse line being further connectedto the signal port of said second valve through a seventh valve, thesupply port of said sixth valve being connected to the signal port ofsaid seventh valve, a line connected to the supply port of said fifthvalve and the signal port of said first valve, eighth and ninth valvesin series with a second constant pressure source for controlling saidlastmentioned line, a connection between said output line and the signalport of said ninth valve, a connection between said signal pulse lineand the signal port of said eighth valve, and a tenth valve in saidlast-mentioned connection, the supply port of said fourth valve beingconnected to the signal port of said tenth valve.
 2. The combinationaccording to claim 1, each of said valves having a body, a relativelynarrow bore in said body, a supply port at one end of said bore, a pairof spaced seats in said bore, a valve disc disposed between said seats,the first of said seats separating said supply and output ports, thesecond seat separating said output and exhaust ports, and a wider borein said body carrying a signal-actuable member whereby pressure at saidsupply or output ports without pressure at said signal port will causesaid disc to engage said second seat and pressure at said signal portwill cause the disc to move against said first seat.
 3. The combinationaccording to claim 2, each valve being further provided with a springurging said valve disc against said second seat.
 4. The combinationaccording to claim 1, further provided with a second controlled member,said line which interconnects the supply port of said fifth valve, thesignal port of said first valve and the output port of said ninth valvecomprising a second output line and controlling said second controlledmember, application of said first signal pressure pressurizing saidsecond output line, release of first said signal pressure maintainingthe pressurized condition of said second output line, application ofsaid second signal pressure exhausting said second output line, andrelease of said second signal pressure maintaining the exhaustedcondition of said second output line.